The ‘Adi’ selection was performed at Rosh Hanikra, the Western Galilee, Israel; by mutating an earlier selection known as ‘Zelig’, in 2001–2002. The mutation resulted as a consequence of multiple subcultures in vitro. In this case, there were 24 subcultures, which is an extremely high number of cycles of multiplications. This type of mutation known as somaclonal variation is induced by an extensive process of tissue culture (ii).
Banana and plantains (Musa spp.) comprise major food sources for more than 400 million people world wide (i). Of the huge volume of fruit production approximately 15% is exported to remote markets. Most banana and plantains are inter or intra hybrids between two species namely Musa acuminata (A genome) and Musa balbisiana (B genome). By far, the most important export variety is Cavendish (a triploid AAA). In the 1950's, this variety replaced “Gros Michel” (not patented) which was almost wiped out due to attacks from a new race of the fungal disease, Fusarium Wilt. Being resistant to the disease combined with wide consumer acceptance in export markets made ‘Cavendish’ irreplaceable. Due to double sterility and the triploid nature of ‘Cavendish’, breeders have very limited tools to improve the germplasm of this variety. Consequently, ‘Cavendish’ bananas suffer from a variety of pests and diseases. In addition, the plants are wind sensitive, have a relatively high stature, short shelf life of the fruit and low tolerance to environmental stresses like lack of or excess water, low mineral nutrition, soil compaction and salinity. Due to the inability of ‘Cavendish’ to cross hybridize there are very limited sources of variability.
Based on somaclonal variation, breeders have selected preferred clones that exhibit better traits in the offspring in comparison to the wild type. Given that these chromosomal changes do not involve recombination events, they are rare and restricted to a narrow range of phenotypic variations. Even with extensive tissue culture cycling, the rate of variation is entirely unpredictable. Nevertheless, some selected clones are highly desired by banana farmers due to their high performance, mainly in terms of yield and plant architecture. Among the most popular selections ‘Gal’ (U.S. patent application Ser. No. 12/042,177 continuation of Ser. No. 11/021,937) and ‘Jaffa’ (U.S. patent application Ser. No. 12/042,177 continuation of Ser. No. 11/021,937) are widely used throughout the world. These last two selections were achieved using a unique genetic tool that has been developed to validate high enough levels of mutations in the “in vitro” processed material (ii). This discovery was achieved through elucidation of a mode of mutation that involves expression of a reto-transposing element known as BanR1 element.
The plant ‘Adi’ that was developed by the inventor was derived from the ‘Cavendish’ selection ‘Zelig’. The parameters used for the selection of ‘Adi’ were low stature and wide girth size. Despite its low stature, ‘Adi’ is characterized as a ‘Cavendish’ with high bunch weight and long fingers. In addition, starch and sucrose content in ‘Adi’ are higher than its originator line Zelig, and also higher than the other known Cavendish selections of ‘Grand Nain’ (not patented) and ‘Williams’ (not patented). An advantage of ‘Adi’'s low stature is easier accessibility to the petiole at harvest time. Easier accessibility to the bunch frees the farm workers from climbing on ladders to reach the bunch. In addition, airplane spraying is a problem in highly populated areas due to the dense population and buildings in the spraying area. ‘Adi’'s low stature facilitates hand or ground machinery spraying and so avoids the need for airplane spraying. Finally, ‘Adi’ is more tolerant to windy conditions than other Cavendish selections.
The mutant was derived by applying stressful tissue culture conditions for a long duration of 24 cycles in culture. Each cycle comprised a one-month duration. Due to its predetermined genetic instability, the ‘Zelig’ line was utilized as an originator of the new selection. ‘Zelig’ is known for its high rate of spontaneous mutations in the field.
This new selection of dessert banana plant, was asexually reproduced by corms in tissue culture by the inventor in Rosh Hanikra, Israel. Unlike its originator line ‘Zelig’, ‘Adi’ has been proven stable in the field for at least three consecutive generations.